MY124718A - "methods and apparatus for spreading and despreading information signals in code division multiple access communications systems" - Google Patents

"methods and apparatus for spreading and despreading information signals in code division multiple access communications systems"

Info

Publication number
MY124718A
MY124718A MYPI20005930A MYPI20005930A MY124718A MY 124718 A MY124718 A MY 124718A MY PI20005930 A MYPI20005930 A MY PI20005930A MY PI20005930 A MYPI20005930 A MY PI20005930A MY 124718 A MY124718 A MY 124718A
Authority
MY
Malaysia
Prior art keywords
spreading
despreading
symbols
rate
cdma
Prior art date
Application number
MYPI20005930A
Inventor
Palenius Torgny
Jonsson Martin
Original Assignee
Ericsson Telefon Ab L M
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ericsson Telefon Ab L M filed Critical Ericsson Telefon Ab L M
Publication of MY124718A publication Critical patent/MY124718A/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2201/00—Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
    • H04B2201/69—Orthogonal indexing scheme relating to spread spectrum techniques in general
    • H04B2201/707—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
    • H04B2201/70703—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation using multiple or variable rates
    • H04B2201/70705—Rate detection

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

CODE DIVISION MULTIPLE ACCESS (CDMA) SPREADING AND DESPREADING TECHNIQUEA ELIMINATE THE NEED FOR FRAME-LENGTH CHIP BUFFERS WITHIN DESPREADING AND DEMODULATION PROCESSORS IN CDMA RECEIVERS. ACCORDING TO THE INVENTION, SUCCESSIVE CDMA FRAMES ARE TRANSMITTED WITH VARIABLE SPREADING FACTORS AND A CONSTANT SPREADING SEQUENCE CHIP RATE TO PROVIDE A VARIABLE DATA THROUGHPUT RATE, EACH TRANSMITTED FRAME THUS INCLUDING A VARIABLE NUMBER OF DATA SYMBOLS AND A VARIABLE NUMBER OF RATE INDICATION SYMBOLS. DURING TRANSMISSION, CHANNELIZATION SPREADING SEQUNCES USED FOR HIGHER DATA RATE FRAMES ARE GUARANTEED TO BE SUBSETS OF CHANNELIZATION SPREADING SEQUENCES USED FOR LOWER DATA RATE FRAMES. CONSEQUENTLY, A CDMA DESPREADING PROCESSOR TO THE INVENTION CAN DESPREAD INCOMING DATA SYMBOLS AS THEY ARRIVE AT A CDMA RECEIVER, STORING THE RESULTING SYMBOLS TO A MEMORY WHICH MUST EXIST IRRESPECTIVE OF THE DESPREADING PROCESS (E.G., WITHIN A DEINTERLEAVER OR ERROR DETECTION AND CORRECTION DECODER). FOR EXAMPLE, INCOMING CHIPS CAN BE DESPREAD USING A MINIMUM ALLOWABLE SPREADING RATE AND , UPON RECEIVING THE RATE INFORMATION SYMBOLS INCLUDED IN THE INCOMING FRAME, A DETERMINATION CAN BE MADE AS TO WHETHER DESPREADING IS COMPLETE. IF IT IS DETERMINED THAT THE FRAME WAS SPREAD USING THE MINIMUM ALLOWABLE SPREADING FACTOR, THEN THE STORED DATA SYMBOLS ARE ACCEPTED AS FINALLY DESPREAD DATA SYMBOLS AND FURTHER RECEPTION PROCESSING CONTINUES DIRECTLY. OTHERWISE, THE STORED DATA SYMBOLS ARE TAKEN TO BE TEMPORARY SYMBOLS WHICH ARE THEN COMBINED, USING THE GUARANTEED RELATIONSHIPS BETWEEN FAST AND SLOW SPREADING SEQUENCES, TO GENERATE THE FINALLY DESPREAD DATA SYMBOLS ADVANTAGEOUSLY, A CDMA RECEIVER ACCORDING TO THE INVENTION CAN THUS OPERATE SUCCESSFULLY WITHOUT REQUIRING A FRAME- LENGTH DESPREADING CHIP BUFFER.(FIG. 5)
MYPI20005930A 1999-12-21 2000-12-18 "methods and apparatus for spreading and despreading information signals in code division multiple access communications systems" MY124718A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/468,111 US6532250B1 (en) 1999-12-21 1999-12-21 Methods and apparatus for spreading and despreading information signals in code division multiple access communications systems

Publications (1)

Publication Number Publication Date
MY124718A true MY124718A (en) 2006-06-30

Family

ID=23858475

Family Applications (1)

Application Number Title Priority Date Filing Date
MYPI20005930A MY124718A (en) 1999-12-21 2000-12-18 "methods and apparatus for spreading and despreading information signals in code division multiple access communications systems"

Country Status (7)

Country Link
US (1) US6532250B1 (en)
EP (1) EP1240725A1 (en)
JP (1) JP2003519953A (en)
CN (1) CN1413393A (en)
AU (1) AU3012301A (en)
MY (1) MY124718A (en)
WO (1) WO2001050620A1 (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9930801D0 (en) * 1999-12-30 2000-02-16 Nokia Networks Oy Spreading factor determination
US6885653B2 (en) * 2000-01-17 2005-04-26 Samsung Electronics Co., Ltd. Apparatus and method for allocating channel using OVSF code for uplink synchronous transmission scheme in a W-CDMA communication system
DE10003734A1 (en) * 2000-01-28 2001-08-02 Bosch Gmbh Robert Detection method and device
US6879576B1 (en) * 2000-09-06 2005-04-12 Qualcomm Incorporated Method and apparatus for processing a physical channel with partial transport format information
US6985510B2 (en) * 2000-12-22 2006-01-10 Qualcomm, Incorporated Method and system for data and voice transmission over shared and dedicated channels
US6552996B2 (en) * 2001-09-18 2003-04-22 Interdigital Communications Corporation OVSF code system and methods
EP1953919A3 (en) * 2002-01-16 2009-09-23 Aviom, Inc. System and method for transmitting audio or video data using multiple levels of protection
US6792037B2 (en) 2002-02-28 2004-09-14 Interdigital Technology Corporation Apparatus and method of searching for known sequences
US7003019B2 (en) 2002-05-22 2006-02-21 Interdigital Technology Corporation Data detection for codes with non-uniform spreading factors
EP1523809A1 (en) * 2002-06-06 2005-04-20 Nokia Corporation System and method for optimized utilization of code resource in communication networks
CN1186950C (en) * 2002-11-13 2005-01-26 大唐移动通信设备有限公司 Demodulating method for customer with variable spectra expanding coefficient
CN1627676B (en) * 2003-12-10 2010-04-14 华为技术有限公司 Method for channel code mapping of downlink shared channel in wideband code division multiple access system
US20080291972A1 (en) * 2004-01-20 2008-11-27 Agency For Science, Technology And Research Method and Transmitter, Receiver and Transceiver Systems for Ultra Widebrand Communication
CN101080877B (en) 2004-12-14 2013-12-18 富士通株式会社 Spreading code allocation method, inverse spreading method, transmitting device, receiving device, communication device, radio base station device, and mobile terminal device
CN101371464A (en) 2005-12-14 2009-02-18 艾利森电话股份有限公司 On-Demand Despreading for Spread Spectrum Receivers
US7646801B2 (en) * 2006-01-26 2010-01-12 Alcatel-Lucent Usa Inc. Method and apparatus for spreading and modulating communication signals
KR100921772B1 (en) * 2007-11-21 2009-10-15 한국전자통신연구원 How to Forward and Receive Safety Messages
CN115189715B (en) * 2021-04-02 2024-06-21 湖南工商大学 Optical transmission device and method based on direct spread spectrum time division multiplexing
CN114095056B (en) * 2021-11-04 2023-07-11 深圳供电局有限公司 Data transmission method, device, equipment and storage medium

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5566206A (en) 1993-06-18 1996-10-15 Qualcomm Incorporated Method and apparatus for determining data rate of transmitted variable rate data in a communications receiver
ZA947317B (en) 1993-09-24 1995-05-10 Qualcomm Inc Multirate serial viterbi decoder for code division multiple access system applications
US5544156A (en) 1994-04-29 1996-08-06 Telefonaktiebolaget Lm Ericsson Direct sequence CDMA coherent uplink detector
US5537410A (en) * 1994-09-15 1996-07-16 Oki Telecom Subsequent frame variable data rate indication method
KR970013834A (en) 1995-08-23 1997-03-29 사와무라 시코우 A computing apparatus of transmission rate
US5796757A (en) 1995-09-15 1998-08-18 Nokia Mobile Phones Ltd. Methods and apparatus for performing rate determination with a variable rate viterbi decoder
JP3409628B2 (en) * 1996-06-19 2003-05-26 株式会社エヌ・ティ・ティ・ドコモ CDMA communication method and group spread modulator
US5831978A (en) * 1996-10-18 1998-11-03 Telefonaktiebolaget L M Ericsson Publ. Method for multiplexing of parallel information streams in a CDMA system
US6108369A (en) * 1997-07-11 2000-08-22 Telefonaktiebolaget Lm Ericsson Channelization code allocation for radio communication systems
US6222875B1 (en) * 1997-07-11 2001-04-24 Telefonaktiebolaget Lm Ericsson (Publ) Low-delay rate detection for variable rate communication systems
US6233231B1 (en) * 1998-12-03 2001-05-15 Motorola, Inc. Data transmission within a spread-spectrum communication system
JP2000341173A (en) * 1999-03-23 2000-12-08 Matsushita Electric Ind Co Ltd Wireless receiving apparatus and wireless receiving method

Also Published As

Publication number Publication date
CN1413393A (en) 2003-04-23
US6532250B1 (en) 2003-03-11
JP2003519953A (en) 2003-06-24
AU3012301A (en) 2001-07-16
EP1240725A1 (en) 2002-09-18
WO2001050620A1 (en) 2001-07-12

Similar Documents

Publication Publication Date Title
MY124718A (en) "methods and apparatus for spreading and despreading information signals in code division multiple access communications systems"
AU746160B2 (en) Rate detection for variable rate CDMA communication system
US7180881B2 (en) Burst detector
AU697493B2 (en) A direct sequence CDMA coherent uplink detector
KR100582217B1 (en) Spread Spectrum Multipath Demodulator for Multichannel Communication Systems
JP2002518960A (en) Method, apparatus and system for realizing base station synchronization and high-speed sector identification
JPH09502593A (en) Method and apparatus for identifying coded communication signals
US6359925B1 (en) Relative-signal-level data detection from a spread-spectrum signal using matched-filter obtained side information
US20020191566A1 (en) Method of cellular communication
US8036181B2 (en) Method and apparatus for reducing multi-user processing in wireless communication systems
US7123647B1 (en) Chip rate base band receiver processor which receives digital information containing symbol information
JP2009060632A (en) Method and apparatus for efficient use of communication resources in communication system
US20030086481A1 (en) Apparatus & method for scalable offline CDMA demodulation
US6366605B1 (en) Spread-spectrum data detection using matched-filter obtained side information
TW200904027A (en) Rake receiver, path searcher and a combined device thereof, mobile communication device and a method for operating a correlator block
US7359430B2 (en) CDMA multicode channel processing
US20030162573A1 (en) Down-link interference cancellation for high-data-rate channels in advanced digital wireless networks
GB2369018A (en) Control channel interference cancellation for a CDMA receiver
CN101401319B (en) A WCDMA system based RAKE receiver set and method
KR100566252B1 (en) Apparatus and method for processing data transmitted by multipath from receiver of mobile communication system
US20080137846A1 (en) Ram- Based Scrambling Code Generator for Cdma
JP2008527910A (en) Efficient maximum ratio synthesizer for CDMA systems
KR20060094076A (en) Frame Synchronization Using Soft Decision in a Universal Mobile Phone System Receiver